Alternative Pathway

Question 1

Why is the alternative pathway part of non specific defense

Answer 1

Because it does not need antibodies to initiate the pathway

Question 2

What is the slowest pathway

Answer 2

Alternative pathway

Question 3

Alternative pathway is triggered by (also known as)

Answer 3

Bacterial endotoxin

Question 4

Describe bacterial endotoxin

Answer 4

A lipopolysaccharide found in the outer membrane of gram negative bacteria

Question 5

What are the other triggers of alternative pathway

Answer 5

1. Yeast cell wall

2. Cobra venom factor

Question 6

What are the 4 serum proteins of the alternative pathway

Answer 6

1. Factor B
2. Factor D
3. Properdin (P)
4. Initiating factor (IF)

Question 7

What’s the main step involved in this pathway

Answer 7

Hydrolysis of factor C3

Question 8

Where is factor C3 present in the body

Answer 8

Blood plasma

Question 9

Factor B combines with C3b where Factor B combines with factor D to cleaves into Ba and Bb. The product formed is

Answer 9

C3bBb

Question 10

C3bBb+ properdin form

Answer 10

C3bBbP which forms C3 convertase

Question 11

C3 convertase cleaves C3 into C3a and C3b in which a product

Answer 11

C3bBb3B

Question 12

C3bBb3B forms C5 convertase which cleaves

Answer 12

C5 into C5b and C5a

C5b forms the membrane attack complex

Question 13

What type of bond does C3 contain

Answer 13

Unstable thio-ester bond

Question 14

What’s the importance of unstable bond

Answer 14

It makes C3 subject to slow spontaneous hydrolysis to C3b and C3a

Question 15

Mammalian cells contain sialic acid. What is the importance of sialic acid

Answer 15

It inactives C3b